Most clamshell style mobile electronic devices used today employ two displays. The two displays include an external display and an internal display. The external display usually has lower visual information content than the internal display and is sometimes referred to as a Caller Line Identification (CLI) display when used in for example mobile phones. The two displays are usually employed in a stacked configuration where the displays are stacked back to back. The stack-up requires a backlight to illuminate the displays.
In some configurations, two backlight units may be sandwiched between the internal display and the external display. In such configurations, each of the two back light units provides the necessary light for one display. In other configurations, a single backlight unit may be sandwiched between the two displays. In yet another configuration, a single two sided display may be sandwiched between two backlight units.
The configurations for display stack-ups, described above, are quite thick. The external display is smaller than the internal display, therefore the external display has a smaller active area. Moreover, in all of the configurations mentioned above, the power required for the backlight units is considerable.
Skilled artisans will appreciate that elements in the figures are illustrated for simplicity and clarity and have not necessarily been drawn to scale. For example, the dimensions of some of the elements in the figures may be exaggerated relative to other elements to help in improving the understanding of the various embodiments.
Further, the figures are for exemplary and illustrative purposes only and are not intended to be complete schematic representations of all elements and/or components necessary to implement any of the various embodiments as such non-represented elements and/or components are readily understood by one skilled in the art.